Acta neurochirurgica. Supplement
-
Acta Neurochir. Suppl. · Jan 1998
Continuous intracranial multimodality monitoring comparing local cerebral blood flow, cerebral perfusion pressure, and microvascular resistance.
Maintaining cerebral perfusion pressure (CPP) above 70 mmHg is currently a mainstay of neurosurgical critical care. Shalmon, et al. recently showed poor correlation between CPP and regional cerebral blood flow (CBF) [1]. To study the relationship between CPP and CBF, at a microvascular level, we retrospectively analyzed multimodality digital data from 12 neurosurgical critical care patients in whom a combined intracranial pressure (ICP)--laser Doppler flowmetry (LDF) probe (Camino, San Diego) had been placed. ⋯ Autoregulation was impaired or absent in all monitored patients. We conclude that with disrupted autoregulation, CPP above 70 mmHg does not necessarily insure adequate levels of cerebral perfusion. Restoration and maintenance of adequate cerebral perfusion should be performed under the guidance of direct CBF monitoring.
-
Acta Neurochir. Suppl. · Jan 1998
Effects of systemic hypothermia and selective brain cooling on ischemic brain damage and swelling.
The present study investigates the neuroprotective effects of temporary mild systemic hypothermia and selective brain cooling against focal cerebral infarction in the rat and the changes of cortical blood flow, and compares these two treatment modalities. In permanent middle cerebral artery (MCA) model, the treatments were induced 15 min following the artery occlusion. The animals were kept at the desired rectal or brain temperature (about 32 degrees C) for 30 min; (each, n = 6) and for 1 hr (each, n = 6), and then allowed to rewarm spontaneously, whereas control animals were kept at normothermia throughout the experiment. ⋯ However, in the selective brain cooling, the reduced blood flow increased from 40% to 70% of baseline value while the brain was rewarmed. The present study indicates that mild systemic hypothermia has much stronger protective effects against focal cerebral infarction and edema than selective brain cooling. The lack of protective effects of selective brain cooling may be caused by post-cooling cerebral hyperemia in the ischemia area.
-
Acta Neurochir. Suppl. · Jan 1998
Randomized Controlled Trial Clinical TrialTreatment of elevated intracranial pressure by infusions of 10% saline in severely head injured patients.
The management of intracranial pressure (ICP) is a factor in outcome of patients with head trauma. However, recent studies have revealed that the current strategies, which have been applied to control ICP for adequate cerebral perfusion, are unsatisfactory. Against this background, the efficacy of short-term infusions of hypertonic saline on ICP was investigated. ⋯ In the individual cases the temporal course of the parameters amplitude and decline interval depict a tendency toward lower and higher values, respectively, under conditions of a generally increasing ICP. As expected, the infusion of hypertonic saline reduces ICP in patients suffering from SHI. The pressure drop, duration and dynamic behaviour are suspected to depend both on the pressure level to reduce and concomitant medications.
-
Acta Neurochir. Suppl. · Jan 1998
Comparative StudyComparative effects of hypothermia, barbiturate, and osmotherapy for cerebral oxygen metabolism, intracranial pressure, and cerebral perfusion pressure in patients with severe head injury.
In order to select the optimal neurointensive treatment for patients with severe head injury and intracranial hypertension, the effects of hypothermia (HT), barbiturates (BT), and osmotic agents (OT) on focal and diffuse cerebral oxygen metabolism were evaluated by means of continuous monitoring of bifrontal regional oxygen saturation (rSO2), jugular bulb oxygen saturation (SjO2), jugular bulb temperature (Tjb), intracranial pressure (ICP), and cerebral perfusion pressure (CPP). ⋯ The therapeutic effects of hypothermia, barbiturates, and osmotherapy on cerebral oxygen metabolism and ICP/CPP are different according to the underlying pathological lesions of patients with severe head injury.
-
Acta Neurochir. Suppl. · Jan 1998
Incidence of intracranial hypertension after severe head injury: a prospective study using the Traumatic Coma Data Bank classification.
Intracranial hypertension (ICH) is a frequent finding in patients with a severe head injury. High intracranial pressure (ICP) has been associated with certain computerized tomography (CT) abnormalities. The classification proposed by Marshall et al. based on CT scan findings, uses the status of the mesencephalic cisterns, the degree of midline shift, and the presence or absence of focal lesions to categorize the patients into different prognostic groups. Our aim in this study was to analyze the ICP evolution pattern in the different groups of lesions of this classification. ⋯ 3 patients had a normal CT scan, and none of them presented intracranial hypertension. In diffuse injury type II, the ICP evolution may be quite different. Patients with bilateral brain swelling (Diffuse Injury III) have a high risk of increased ICP (63.2%). Although in our study the frequency of Diffuse Injury IV was low, all patients in this category had a refractory ICP. In the category of evacuated mass lesions, two thirds of the patients presented an intracranial hypertension. In one third, ICP was refractory to treatment. 85% of patients with a non-evacuated mass lesion showed an increased ICP.